Variable speed transmission



March 30, 1943. A. M. MADLE} 2,315,067

VARIABLE SPEED TRANSMISSION Filed Sept. 22. 1941 35919.1. II at a 2 3 INVENTOR.

BY \gk m. UOQWQUJK ATTORNEY.

UNITED STATES PATENT OFFICE VARIABLE SPEED TRANSMISSION Alain M. Madl, Milwaukee, Wis., assignor to Graham Transmissions Inc., Milwaukee, Wis., a corporation of Delaware Application September 22, 1941, Serial No. 411,844

6 Claims.

This invention is an improvement in variable speed planetary transmissions of the friction type including longitudinally tapered planet rollers and an axially movable control ring encircling tageous in transition periods. And the nonplanetary weight may be varied without altering the geometry of the machine.

Other objects and advantages reside in certain the rollers and adjustable lengthwise thereof to novel features of the construction, arrangement, control their motion. and combination of parts, which will be herein- The present application is a continuation in after e u y e r ed d particularly part of my application for Variable speed transpointed out in the appended m reference missions, filed March 11, l940.seria1No. 323,320. ing b d to the a mp nying rawing formin One structural type of such transmission inapart of this p a on. and in which: cludes a rotary carrier with the planet rollers Figure 1 is a V ew n e Vertical. longihaving their small ends pivoted r fulcrumed on tudinal cross section showing a transmission conthe rotary carrier nd their large d supported structed in accordance with the present invenon the carrier so as to be constrained to radial lion, parts being shown n e ev f t e sa swinging or tilting movement into pressure conof illustration; tact with the control ring. Means must be pro- Figure 5 a w ta in ers v t vided to force the planet rollers into pressure Cross section On line Figure and contact with their control ring in order that the Figure 3 is a v w in transverse, vertical, cros requisite traction will be developed between the Section taken o e of Figure 1, with parts rollers and the ring. shown in elevation for the sake of simplicity in The present invention proposes to utilize cenillustrationtrifugal force as the preponderant, or i some Referring to the drawing, it will be seen that a instances as the sole, source of force which devariable speed planetary ss n ody velops pressure contact or traction between the the present invention Comprises a housing desigrollers and their control ring. This is accomnated generally at a d having e ovab e end plished by attaching a non-planetary Weight r plates 2 and 3 carrying the ball bearing assemblies block of appropriately substantial mass to the 4 and 5 the -D t nd Ou -D l h f s desig bearing for the large end of each roller. The hated at 5 d pe ve y- A rotary Carrier weights or blocks are disposed as far distant as ignated generally at 8 is supported for rotation practicable from the axis of rotation of the carin e usi I and is operat y i e re a e rier for the rollers, thereby establishing a maxiwith the -D d t-l nt s afts 6 and 7. mum centrifugal radius and the maximum cen- Two longitudinal y p r d 1' Conical pl n y trifugal force for any given R. P. M. And since rollers designated all l5 are mounted on the the non-planetary blocks or weights are attached rotary carrier 8 for rotation therewith and with to the bearings at the large ends of the rollers, respect thereto. d fo t ng o racking mevetheir centrifugal effect acts through the maximum merit transversely r radially o leverage available. Consequently, the centrifugal A control traction ring encircles e moment of the non-planetary weights t th planet rollers l5 and is axially shiftable lengthpoints of contact of the rollers and their control Wise thereof to control their motion. ring is many times greater than that of the 40 Each roller i5 is provided with journals or planetary rollers at such points. trunnions I1 and I8 at its ends. A spherical Y utilizing t centrifugal force of a bearing assembly [9 cooperates with the trunnion planetary weight as the principal or prepo ll of each roller i5 and is in turn supported and source of force to develop pressure contact bereleasably secured in an opening 20 provided tween the rollers and their ring, a definite loading therefor in the acent end plate 9 of the carrier. is had, the transmission is unloaded when not The bearing assembl '9 is desi ed tosu rt running, the control ring may be readily shifted th 1 t n f y i lengthwise of the rollers, when the transmission e p ane 9 er f on abc'ut Its own axis is stationary, to pre-select the speed at which the and rocking or mung movement transversely tr i is to operate, and the transmission or radlally wlth respect to the rotary carrier. For is rendered easy to assemble. And further, this this Purpose each bearing s embly I9 may have permits th m t f inertia f the planetary its outer race provided with a spherical inner rollers to be kept as small as possible. The use ace engageable with the bal s n B- man of a larger planetary roller and the larger moment common in this type of ball hearing, or its outer of inertia in such rollers is obviously disadvanrace m y have a spherical Outer Surface Slldably interfltted with a correspondingly formed wall of the opening 20.

Each trunnion l8 at the large end of each planetary roller I is supported for rotation in a double ball bearing assembly 22, which in turn is mounted in a guide block or bearing support 23. Each guide block or bearing support 23 is slidably fitted in a radial slot or guide-way provided therefor in the rotary carrier 8, the slot or guideway 24 extending diametrically through the carrier at the end thereof adjacent the in-put shaft 6.

Each guide block or bearing support 23 has integrally formed therewith, or suitably attached thereto, a weight 25. The weights are integral with or attached to the outer portions of the guide blocks, and preferably are in the form of segments of a circle, the weights overhanging the guide blocks 24 and having their outer peripheries closely adjacent to, though slightly spaced from, the end wall of the housing I. By combining these weights in this manner with the guide blocks they are non-planetary in character for they do not rotate with the rollers and hence they may be eccentrically disposed without unbalancing the rollers, and moreover they are so located as to exert the maximum contrifugal effect and may be given the appropriate dimensions.

Just beyond each bearing l9 each trunnion I! has a planet pinion 35 keyed or otherwise fixed thereto. The two planet pinions 35 mesh with an internal ring gear 36 which may be formed integral or otherwise suitably fixed to the output shaft 1.

The end of the rotary carrier 8 adjacent the ring gear 36 is supported thereon, and for this purpose a stud shaft 3'! is provided and has a portion press-fitted into an opening 31' in the carrier 8. A projecting portion of the said shaft 31 is piloted into the ring gear 36 in that it is mounted in a roller bearing 38 supported in a recess 39 in the hub portion of the ring gear 36.

The traction or control ring I6 is formed at one end with an annular or band-like structure 40, which is of considerable length in order to afford the desired bearing contact essential. to prevent canting or cooking of the ring. The band-like structure of the control ring is slidably supported on appropriately machined guide-ways or lands 4! provided therefor on the interior of the housing I and is constrained to sliding motion and held against rotation by means of keys 43 secured with screws 44 and key-ways 45 provided therefor in the periphery of the band-like structure 40, the keys 43 also being slidably interfitted in key-ways 46 provided therefor on certain of the guide-ways or lands 4|, as clearly shown in Figures 1 and 3.

The control ring may be adjusted from a rotatable operating or control shaft 54 having a yoke 55 operatively interrelated with the control ring. Details of the control means per se form no part of the present invention, and are fully shown and described in my U. S. Letters Patent 2,178,399, granted October 31, 1939.

On Figure 1 the point A is the resultant point of the summation of the centers of gravity of the planetary roller l5 and the parts associated therewith and partaking of a planetary motion; the point B is the resultant point of the summation of the centers of gravity of the non-planetary guide block 23 and th non-planetary weight 25. In the typical design illustrated, the centrifugal weight W of the non-planetary block effective at the point B is nearly five times as great as the centrifugal weight w of the planetary roller l5 effective at the point A. It. is to be noted that this arises not only from the greater relative mass of the non-planetary block as compared to that of the planetary roller, but to its greater distance R from the central axis as compared to r. In addition, the centrifugal weight W of the non-planetary block acts through the lever arm L which is considerably greater than the lever arm I of the centrifugal weight w of the planetary roller. As a consequence, the loading moment WL of the non-planetary weight is approximately seven times as great in the actual commercial design illustrated as the loading moment wt of the planetary roller. .In other words. approximately seven-eighths of. the tractional pressure eiiective at the point of contact between the ring and roller is here derived from the nonplanetary weight.

While I have shown and described one construction in which the invention may be advantageously embodied, it is to be understood that the construction shown has been selected merely for the purpose of illustration or example, and that various changes in the size, shape, and arrangement of the parts may be made without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. A variable speed transmission of the character described comprising a rotary carrier, an axially movable control ring, a plurality of inclined conical planetary rollers, a bearing supporting the small end of each roller on the carrier for rotation therewith and with respect thereto and for rocking movement into pressure contact with said ring, said carrier having a radial guideway adjacent the large ends of the rollers, a bearing for the large end of each roller, a bearing block carrying each of said last-named bearings and fitted for radial sliding movement in the adjacent radial guideway, and means utilizing centrifugal force to develop pressure contact between said rollers and said ring, and including a non-planetary weight fixed to each of said bearing blocks, and constituted to provide a centrifugal ellect greater than that of the planetary rollers.

2. A variable speed transmission of the character described comprising a rotary carrier, an axially movable control ring, an inclined planetary roller, means supporting the small end of the roller on the carrier for rotation therewith and with respect thereto and for tilting movement in a radial plane into engagement with said ring, a bearing for the large end of the roller, and means utilizing centrifugal force as the entire source of force to develop pressure contact between said roller and said ring and including a non-planetary weighted block fastened to said bearing and constituted to provide a centrifugal effect substantially greater than that of the planetary roller.

3. A variable speed transmission of the character described comprising a. rotary carrier, an axially movable control ring, an inclined conical planetary roller, means supporting the small end of the roller on the carrier for rotation therewith and with respect thereto and for tilting movement into engagement with said ring, means coacting with the large ends of the roller and the carrier to constrain the roller to rotate with the carrier andto tilting movement in a radial plane into pressure contact with said ring, and

means utilizing centrifugal force to develop pressure contact between said roller and said ring and including an eccentric non-planetary weight connected to the large end of the roller and constituted to provide a centrifugal effect substantially greater than that of the planetary roller.

4. A variable speed transmission of the character described comprising a rotary carrier, an axially movable control ring, an inclined conical planetary roller having the small end fulcrumed on the carrier and constrained at its large end for tilting movement in a radial plane into pressure contact with the ring, and means utilizing centrifugal force as the entire source of force to develop pressure contact between said roller and said ring and coacting with the large end of the roller and constituted to exert on the large end of the roller a centrifugal force of a magnitude substantially greater than that of the planetary roller.

5. A variable speed transmission oi the character described comprising a rotary carrier, an axially movable control ring, an inclined conical planetary roller having its small end f-ulcrumed on the carrier and constrained at its large end to tilting movement in a radial plane into pressure contact with the ring, and means utilizing centrifugal force as the source of force to de velop pressure contact between said roller and said ring and including a non-planetary weight interconnected with the large end of the roller and constituted to exert centrifugal force on the large end of the roller of a magnitude substantially greater than that of the planetaly roller.

6. A variable speed transmission of the character described comprising a rotary carrier, an axially movable control ring, an inclined conical planetary roller having its small and fulcrumed on the carrier, a bearing for the large end of the roller, and means utilizing centrifugal force to develop pressure contact between the roller and the ring and including a guide block for said bearing supported on the carrier for sliding movement radially with respect thereto, and an eccentric non-planetary weight fixed to the guide block and applying centrifugal force to the large end of the roller in an amount substantially greater than that of the planetary roller.

ALAIN M. MADLE. 

